Switch device



Aug. 1.4, 1934.

R. J. BUSH SWITCH DEVICE Filed Aug. 27, 1932 Ill! E Humm. A

@um lm! A TTORNE Y.

Patented Aug. 14, 1934 SWITCH DEVICE Rankin J. Bush, Jeannette, Pa.,assigner to The Westinghouse Airv Brake Company, Wilmer* ding, Pa., acorporation of Pennsylvania Application August 27, 1932, Serial No.630,733

Claims.

This invention relates to switch devices and particularly to switches ofthe snap action type for controlling control circuits and particularlythe control circuits of electrically driven vehicles,

-5 wherein the switch device is actuated and controlled by the controlmechanism of the pneumatic brake valve associated with the brake systemof the vehicle.

An object of the invention is to provide a 101switch device, wherein theswitch contacts are moved into conductive engagement with a wipingaction by reason of a combined longitudinal and angular movementimparted to the movable contact at the time of the engagement with itsl5. cooperating Contact, thereby insuringr` clean contact surfaceshaving low contact resistance.

Another object of the invention is to provide a switch device wherein aswitch normally biased toward open position, is closed by a manually;.'actuated operating device associated with the brake valve andretained in closed position independently of the operating device,andwherein the switch is released to openposition by a trip Y mechanismthat is manually retained inoperative 25.` to release the switch by theoperating device.

A further object of the invention is to provide a switch device havingthe above noted characteristics, wherein adjustable means are providedfor determining the operative relation of the op- Jerating member withrespect to the switch device.

A further object of the invention is to provide an improved switchdevice that is simple and rugged in construction, inexpensive tomanufacture, and readily accessible for inspection and repair.

These and other objects of the invention that will be made apparentthroughout the further description thereof, are attained by means ofaiolthe switch device hereinafter described and iliustrated in theaccompanyingdrawing, whereinv Fig. 1 is an elevational View of theimproved switch device, partially in section, showing the movable switchmember in open position; 45. Fig. 2 is a view similar to that of Fig. 1showing the movable switch member in an intermediate closed position;

Fig. 3 is a top plan View, partially in section, of the switch devicewith the parts shown in the positions shown in Fig. 2; and

Fig. 4 is a plan elevational view, partially in section of the movableswitch contact member.

Referring to the drawing, the kswitch deviceV comprises a base member 5preferably made of insulating material, a sheet'metal frame 6 forsupporting the switch operating mechanism and which is secured tothebase by means of bolts 7, contact supporting brackets 8 secured to thebase 5, and a lguide support 9 for supporting a tubular guide member1-1, the purpose of which 00 will hereinafter appear.

Fixed contacts 12 are mountedupon the brackets 8 and are conductivelyconnected to terminals 13 of the conductors 14V of the electricalcontrol circuit to which the switch device is electrically connected.The fixed contacts 12 are adapted tc be conductively connected orbridged by a movable switch member 15, which comprises a metal bridgingcontact member or arm 1,6 that is embedded inra block 17 of insulatingmaterial 70 and which is provided with contact buttons '18.' that areadapted to make butt contact with the xedcontacts 12.

Asindicated in Fig. 4, the insulating block 17 is provided with a squaremetal bushing 19 hav- ,751

ing a square opening 21 extending therethrough for receiving a-.squareshaft or rod 22, which fits loosely within the bushing 19 so that theblock 17 and bridging contact member i6 may move longitudinally withrespect tothe shaft 22 8()l by means of a cotter pin 24. The movablecontactfrnember 15 is yieldingly held against the col- Y lar 23 by meansofa spring 26 which surrounds the shaft 22 and which is disposed betweenthe insulating block 17 and a collar 27 secured to the shaft 22 adjacentone endr thereof.

The shaft 22is provided with a cylindrical portion 28 ofreduceddiameter, which is provided with` an-fenlargedhead 29 havingaspherical sur'- face 30, the head. 29 being adapted to flt within theguide tube 11, as indicated in Figs. 1 andi 2, 100

and to support the left end of the shaft 22 for longitudinal and angularmovement of the shaft, the angular movement being possible by reason ofthe spherical surface of the head 29 and the reduced diameter of theportion 28.

The right end of the shaft 22 is pivotally supported by means of rockinglinks 31 that are pivctally connected to a pin 32 carried on-the rightend oi the shaft 22 and to the supporting framel 6by means of a pin 33.As the links-3l swing 1l@ from their extreme right position shown inFig. 1, to the extreme left position shown in Fig. 2, the right end ofthe shaft 22 is moved through an arc and consequently, angular movementis imparted to the shaft as well as longitudinal movement.

When the shaft 22 is moved toward the left, the contact buttons 18engage the fixed contacts 12 and arrest longitudinal movement of theswitch contact arm 16 before the movement of the shaft 22 is completedand while the shaft 22 is in an angular position with respect to itsnormal horizontal position. Accordingly, further longitudinal movementof the shaft 22 relative to the switch arm 16, causes the spring 26 tobe compressed, so that the contact buttons 18 are maintained inengagement with the contacts 12, by the pressure of the spring 26, asthe buttons are moved laterally across the faces of the contacts 12 witha wiping action, in a manner to be hereinafter more fully described.Since the switch member 15 is mountedfor universal movement upon theshaft 22, the buttons 18 are free to accommodate their position withrespect to the contacts 12, so as to secure an extensive surface Vtosurface contact, regardless of slight discrepancies of alignment of thecontacts 12. n

The switch shaft 22 is lactuated by means of a toggle device comprisinglinks 34 and 35 that are pivotally connected by means of a knee pivot36. The link 34 comprises two fiat links disposed on opposite sides ofthe link 35 and which straddle the collar 27 on the end of the shaft 22.The left end of the links 34 are pivotally connected to the pivotshaft32, to which the link 31 is pivotally connected. The right end ofthe link 35 is pivotally connected to a pivot shaft k37 that isfastenedtothe frame 6 by means of cotter pin 38.

As shown in Fig. l, the toggle links 34 and 35 are in the released orcollapsed position, to which position they have been moved by a spring39 that is centered by the end of the bushing 11 projecting from thesupporting bracket 9, and which is disposed between the guide support 9rand the co1- lar 23 of the shaft 22. Y

The toggle links are moved tothe made position, shown in Fig. 2, bymeans of a bell-crank` lever 41 that is pivotally mounted for rotationaboutV a shaft 42 that is fastened to the frame 6 by l means of cotterpins 40. The shortarm of the: .lever 41 is bifurcatedand constitutes apair of f g'the link 35 at points within the opening andrnove it so asto move the .links of the toggle to made` position, as shown in Fig. 2,movement thereof. f

.Whenithe toggle links 34 and'35 are in the reor to cause release:leased position, ,as shown in Fig; 1, the switch member is in openposition. In order to close the switch, the toggle links are moved ktothe made position shown in Fig. 2 in a manner to be hereinafterdescribed. The lrst rmovement of the llink 34 causes both longitudinaland angular movement of the shaft 22 as the pivot pin 32 is moveddownward in an arc as the link 31 turns about thepivot 33 to a verticalposition. Further movement causes an upward movement of the pivot pin 32as the contact 18 of the switch member engages thecontact member 12. Asthe knee pivot 36 `of the toggle passes over vcenten-as when it crossesthe center line A, the-spring 39 resting against the stop 46, thuscausing a quick vertical or transverse movement of the contacts 18 overthe contact members 12, until the angular movement of the shaft isarrested by engagement of the reduced portion of the shaft 22 with theright end of the bushing l1.

The bell-crank lever 41 is adapted to be4 operated in acounter-clockwise direction for moving the toggle links to the madeposition, wherein the movable switch member is in the closed position,by means of a rod 47 that is connected to the foot pedal, not shown, ofa brake valve device, not shown, for controlling the brakes of avehicle, not shown. The rod 47 is adapted to be held in elevatedposition for insuring closed position of the switch, by the foot of theoperator, and is moved into inoperative relation with the switch deviceto permit opening movement thereof, when the rod is moved downwardly aswhen the foot pedal is moved to emergency brake position by .ieoperator, or by gravity, or a spring, not shown, as when the operatorremoves his/footentirely from the footpedal. The upper end of theoperating rod 47 is adapted to` engage an adjustment screw 48 that isrthreaded into an arm 49 integral with the bell-crank lever 41, andwhich is locked in adjusted position by means of a lock nut 51.

As indicated in Fig. 2, the rod 47 has `just rotated Ythe bell-cranklever 41 in a counterclockwise direction andcaused the trip shaft 44 tomove the toggle links from the release position shown in Fig. 1, pasttheir dead center position, so that they may snap to the made positionvshown in Fig. 2, wherein themovable switch member 15 is in the closedposition. The bellcrank lever 41 is biased toward the switch `openposition, shown in Fig.` l, by means of a spring 52 that surrounds aguide rod 53 that is pvotallyv disposed between the bracket 56 and theenlargedv head 57 of the guide rod 53. When the operating rod 47 isdepressed, the bell-crank lever 41 is moved in a clockwise direction bythe spring 52 and causes the trip shaft ,44 to engage the link 35 andmove the knee pivot shaft 36 of the toggle device to a point above thecenter line A. After the knee pivot shaft 36 passes above the centerline A, the spring 39 acting on the collar 23 causes the toggle links tocollapse and move with a snap action tothe released position, shown in iFig. 1, thereby snapping the movable switch member 15 to the openposition shown in Fig. 1, so that any arc drawn between the contacts 12and the contact buttons '18 is instantly extinguished and the circuitthrough the switch` interrupted. k Y

By employing a toggle device for operating the switch shaft 22 having anover center position, when the toggle is moved to made position, the

force exerted by the spring 39, tending to move the switch member 15 toopen position, cannot be applied to the operating rod 47 and the forcetending to move the operating rod 47 downwardly screw 48, the operativerelation of the switch device to the operating rod 47 and the brakevalve device associated therewith, may be varied A acting .on the shaft22 forces the link 34 of the itogeletoturn about Ythe Divot 36 which iSthen to suit requirements. y

While I have discloseda switch device that is fito particularly adaptedfor controlling the control circuit of a circuit breaker for controllingthe motor circuit of a vehicle, and which is associated with a brakevalve device. for controlling the 35 brakes of the vehicle, it isobvious that the switch device is applicable to other uses and thatchanges, omissions and additions may be made in the switch deviceconstruction without departing from the spirit of the invention.y

Having now described my invention, what I claim as new and desire tosecure by Letters Patent, is:

l. A switch device comprising a contact member, an operating shaftslidably supported at one l end for longitudinal and angular. movement,a

pivoted lever for supporting the other end of the shaft for impartinglongitudinal and angular movement to said shaft, a movable switch memberyieldingly mounted upon the shaft for limited 2o universal movement withrespect thereto and lh at adapted to engage said contact member beorethe shaft has completed its longitudinal and angular movement forcausing the switch member to engage the contact member with a wipingmovement and an over-center toggle device movable from released positionto an over-center made position, so connected to said shaft that itmoves to over-center position after the switch member has engaged saidcontact member, and

moves the shaft angularly after it has moved over center.

2. A switch device comprising a support, a contact member mountedthereon, lan operating bar supported at one end upon the support for`longitudinal and angular movement, a pivoted `lever pivotally mountedon the support for supporting the other end of the bar for impartinglongitudinal and angular movement to said bar, a movable switch memberfor engaging said cony.tact member and mounted upon the bar `for limitedlongitudinal movement with respect thereto, a spring disposed betweenthe bar and said switch member for biasing the latter in the directionof said contact member, a spring disposed between said support and saidbar for bias- `ing the bar in a direction away from said contact member,and means including an over-center toggle device movable from releasedto made positionl for moving the bar longitudinally .against the tensionof said spring and for imparting angular movement to said bar after thetoggle device has moved over center.

3. A switch device comprising a contact member, a movable switch memberfor engaging said .contact member, an operating shaft for supportingsaid switch member and slidably supported at one end for longitudinaland angular movement, a pivoted lever for supporting the other end ofsai-d shaft for moving said shaft angularly and longitudinally formoving said switch member into engagement with said contact member and atoggle device for moving said lever movable to made and releasedpositions and so connected to said shaft that it retains the said shaftand switch member in closed position when the toggle device is in madeposition.

4. A switch device comprising a contact member, a movable switch memberfor engaging said contact member, an operating shaft for supporting saidswitch member and slidably supported at one end for permittinglongitudinal and angular movement of said shaft, a toggle device, meansincluding a link of said toggle device pivotally connected to the otherend of said shaft,

y.for moving the shaft longitudinally for moving said switch member intoengagement with said contact member and for; imparting angulaimovementto said shaft for moving said switch member transversely over saidcontact member during the final movement `of said shaft.

5,. A switch device comprisinga contact member, a movable switch memberfor engaging said contact member,Y an operating shaft foisupporting saidswitch memb r and slidably supported atone end'for permittinglongitudinal and `angular movement of said shaft, a toggle device, meansincluding a link of said toggle device pivotally connected tothe otherend of said shaft, for moving the shaft longitudinally, a means crsupportingA said other end of said shaftfor imparting angula"rnc-'vement thereto as the shaft is 'moved.longitudinally by said togglelink for moving said switch member into engagement with said contactmember, and means having a lost motion connection to said toggle devicefor moving it to its operative positions.

6. A switch device comprising a contact member, a movable switch memberfor engaging said contact member, a spring associated with said switchmember for moving said switch member to open position, a toggle devicehaving made and released positions, and so connected to said switchmember that when the toggle device is in made position it holds theswitch member in closed position against the action of said spring, anda second spring acting on said switch member and adapted to be placedunder tension when said toggle is moved from released to made positions,and adapted to cause release movement of said toggle.

'7. A switch device comprising a contact member, a movable switch memberfor engaging said contact member, a spring associated with said switchmember for moving said switch member to open position, a toggle devicehaving made and released positions and so connected to said switchmember that when the toggle device is in made position it holds theswitch member in closed position against the action of said spring,means for moving said toggle device toward made and released positions,and a second spring adapted `to be tensioned by said means for actuatingsaid means for initiating movement of said toggle to released position.

8. A switch device comprising a contact member, a ymovable switch memberfor engaging said contact member, a spring associated with said switchmember for moving said switch member to open position, a toggle devicehaving made and released positions and so connected to said switchmember that when the toggle device is in made position it holds theswitch member in closed position against the action of said spring,means for moving said toggle device toward made and released positions,a second spring adapted to be tensioned by said means for actuating saidmeans for initiating movement of said toggle to released position, and amanually operated means for actuating said means for moving said toggleto made position.

9. A switch device comprising a contact member, a movable switch memberfor engaging said contact member, a spring associated with said switchmember for moving sai-d switch member to open position, a toggle devicehaving made and released positions and so connected to said switchmember that when the toggle device is in vmade position it holds theswitch member in closed position against the action of said spring,means for moving said toggle device toward made and released positions,second spring adapted to .be tensoned by said means for actuating saidmeans for initiating movement of said toggle to released position, ameans movable manually a predetermined distance and movable relative toand `actuating said means for moving said toggle t-o made position, .andadjustable means cooperating with the iirst and second said means fordetermining the degree of relative movement of spring normally biasingsaid vshaft in a direction away from said contact member, and means forsupporting one end of said shaft for longitudinal and vangular movement,means for limiting angular movement of said shaft, and an operatingmeans for imparting longitudinal and angular movement to said shaftcomprising a pair of toggle links connected by a knee pivot, andconnected respectively to the Vother end of said shaft and to saidsupport by separate pivots, the said knee pivot being movable fromrelease position of said links to made position thereof against theaction of said spring and across ,a center line through said pivots sothat said other end of said shaft is moved angularly by said springacting with said toggle link after said knee pivot has crossed saidcenter line.

RANKIN J. BUSH.

